Thermally controlled fluid flow regulating or shut-off valves

Abstract

A fluid flow regulating or shut-off valve of the kind having a bimetallic element which regulates or opens and closes a flow passage through the valve in dependence upon temperature is provided with at least one electrically heatable PTC-element which is in thermal contact with the bimetallic element. Heating of the PTC-element by control of the supply of electricity to it thus controls the operation of the valve. The bimetallic element is preferably in the form of a snap-acting bending bimetallic plate which is heated by radiation from the PTC-element and which itself forms the valve closure member. With the bimetallic plate snapped in one direction, a passage through the valve is opened, but when the plate snaps in the other direction, it bears against a sealing ring surrounding a valve opening within the valve to close and seal the opening and thus shut the valve.

I claim: 
     
       1. A fluid flow control valve comprising a thermally responsive bimetallic element, means defining a fluid flow passage through said valve, means defining a valve seat located to be engaged and disengaged by said bimetallic element to closed and open said fluid flow passage, a thermally conductive member, means mounting said thermally conductive member together with said bimetallic element to define therebetween an enclosed volume insolated from said fluid flow passage, and temperature varying means mounted on said thermally conductive member in thermally conductive relationship with said bimetallic element operating to control said bimetallic element to open and close said valve. 
     
     
       2. A valve according to claim 1 wherein said temperature varying means is a PTC-element. 
     
     
       3. A valve according to claim 1, wherein said temperature varying means is mounted against a side of said thermally conductive member opposite the side thereof on which said bimetallic element is located. 
     
     
       4. A valve according to claim 1, further comprising a valve cover attached to said base, said thermally conductive member being held in clamped engagement between said valve base and said valve cover, and spacer means spacing said bimetallic element from said thermally conductive member to form said enclosed volume therebetween, said valve base and valve cover being arranged to effect a clamping action tending to produce a sealing effect between said bimetallic element and said thermally conductive member. 
     
     
       5. A valve according to claim 4, further comprising top hat-shaped holder means interposed between said valve base and said bimetallic element, said bimetallic element having a periphery clamped thereabout between said spacer means and said top hat-shaped holder means. 
     
     
       6. A valve according to claim 2, further comprising means holding said PTC element against said thermally conductive member on the side thereof remote from the side upon which said bimetallic element is located, a housing enclosing said valve, electrical plug contacts extending through said housing and means electrically connecting said PTC element to said plug contacts. 
     
     
       7. A valve according to claim 6, wherein said means holding said PTC element against said thermally conductive member includes elastic means elastically pressing said element against said member. 
     
     
       8. A valve according to claim 3, wherein said bimetallic element comprises a peripheral portion and a central portion and wherein said valve seat is formed by a sealing ring surrounding said means defining a fluid flow passage, said valve further comprising means clamping said peripheral portion of said bimetallic element in a position wherein said central portion thereof extends over said sealing ring, said bimetallic element being movable between a position in contact with said sealing ring to close said fluid flow passage and a position away from said sealing ring to open said fluid flow passage in response to said temperature varying means.